Base..cream together margarine,brown sugar and flour until well blended and mixture sticks together. Press into 9x13 pan. Bake at 350* for 20-25 min or until light golden. Cool while preparing filling.

filling...Heat sweetened condensed milk and margarine in heavy pan,stirring constantly over med heat for 5-10 min or until thickened. Spread over cooled base. Bake at 350* for 12-15 min or until golden. Sprinkle chocolate chips evenly over the top. Bake for 2 min longer or until chocolate is shiny and soft. Remove from oven. Spread chocolate evenly. Sprinkle toffee bits on top,pressing lightly into chocolate. Cool completely and cut into bars.